1. Field of the Invention
This invention relates to refrigeration apparatus and in particular to means for controlling timing of the harvesting of ice from an ice maker as a function of the temperature of the compartment in which the ice maker is disposed.
2. Description of the Background Art
It is conventional in ice maker controls to effect a harvesting operation of the formed ice as a function of the temperature within the freezing compartment in which the ice maker is disposed. The length of the timed ice making cycle is varied according to the sensed temperature, and the length of the ice making cycle is based on an assumption that the rate at which the ice forms is a linear function of the temperature within the freezing compartment.
It has been found, however, that such controls are at times inaccurate in initiating the harvesting cycle either before the ice is completely formed, or maintaining the ice making cycle for too long a period, wasting energy in the continual cooling of the completely formed ice before the harvesting cycle is initiated.
A number of different systems for controlling the ice making and harvesting cycles have been disclosed in prior art patents. Illustratively, in U.S. Pat. No. 3,648,478 of William J. Linstromberg, which patent is owned by the assignee hereof, an ice maker control is disclosed wherein the means for timing the ice making operation is caused to operate only when the compressor is energized so as to cause the compressor run time to determine the length of the ice making cycle. Thus, after a predetermined amount of compressor run time is accumulated, the control automatically terminates the ice making operation and initiates the ice harvesting operation.
Another form of ice making apparatus means is illustrated in U.S. Pat. No. 3,714,794 of William J. Linstromberg et al, which patent is also owned by the assignee hereof. In this patent, a timer motor operates continuously other than when the temperature in the freezer compartment rises above a preselected temperature at which it is undesirable to effect further operation of the ice maker.